Electrical apparatus



Sept. 23, 1924. 1,509,666

J. G. CAMPBELL I ELECTRI CAL APPARATUS Filed July 30 1923 [RUE]? LTD/2n 5. Ca 2]].

NAM 660W Patented Sept. 23, 1924.

UNITED STATES PATENT OFFICE.

JOHN G. CAMPBELL, OF DAYTON, OHIO, ASSIGNOR TO DELCO-LIGHT COMPANY, OF

' DAYTON, OHIO, A CDRPORATION OF DELAWARE.

ELECTRICAL APPARATUS.

Application filed July 30, 1923. Serial No. 654,504.

To all whom it may concern:

Be it known that I, J OHN G. CAMPBELL, a citizen of the United States of America, residing at Dayton, county of Montgomery, and State of Ohio, have invented certain new and useful Improvements in Electrical Apparatus, of which the following is a full, clear, and exact description.

The present invention relates to brush riggings for dynamoelectric machine and particularly to that type of rigging in which the brush is slidably mounted in a brush holder.

One of the objects of the present invention is to provide a rigging which is simple in construction and which can be readily assembled on the dynamo-electric machine.

Another object of the present invention is to prevent the chattering of the brushes in the brush holders.

Other and further objects of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of one form of the present invention is clearly shown.

In the drawings:

Fig. 1 is an end view of a motor showing the present invention partly in section applied thereto; and

Fig. 2 is a fragmentary view looking in the direction of arrow 2.

Referring to the drawings, 20 is the field frame of a dynamo-electric machine upon which is rotatably mounted a brush plate 21. The plate 21 is mounted within a recess in the field frame of a depth slightly less than the thickness of the plate 21; and plate 21 is held in the desired place by screws 22. Plate 21 is formed with inwardly extending portions 24 to which brush holders 25 are secured by rivets 26.

Each brush holder 25 comprises a U- shaped member having side walls 27 and 28 and an end wall 29. The holder 25 together with the plate 21 forms a guide for a brush 30. Walls 27 and 28 are each provided with aligned slots 31 and 32 respectively, the slot 32 being longer than the slot 31. A brush clip 33 is loosely mounted on the end of the brush 30 and provides a short side wall 34 and a relatively long side wall 35 which are adapted to move within the slots 31 and 32 respectively. Clip 33 is provided with ears 36 and 37 which are connected by springs 38 with the brush clips of the adjacent brushes.

It will be observed thatthe side walls 27 and 28 of the brush holder 25 are disposed at an angle to a radial line passing through the center of the armature and the point of contact of the brush 30 with the commutator. The springs 38 acting upon the clips.

pull the brushes inwardly in a general radial direction into contact with the side wall 28 of the clip. Owing to the angular relation of the clip with reference to the armature, there is a tendency under some conditions for the lower end of the brush 30 to leave the wall 27 and engage the wall 28. This may result in chattering of the brush 30, particularly when the armature rotates in a counterclockwise direction as viewed in Fig. 1. The long side wall 35 of the clip 33 effectively prevents such chattering by forcing the lower end of the brush 30 against the wall 27 and holding it in this position.

The present invention provides a brush rigging which is simple in construction, quiet in operation, and which prevents the chattering of brushes in either direction of rotation of the armature, although as will be readily understood, rotation of the armature in a counterclockwise direction acts upon the brush in such a manner as to cooperate with the brush rigging in holding the brush in position against the wall 27 as hereinabove explained. While the side walls 27 and 28 of the clips are provided with walls 31 and 32 for the reception of the brush holders 25 it will be observed upon reference to Fig. 2 that the walls are relatively narrow and do not shorten the long guiding surface provided by the walls 27 and 28.

The present invention provides a brush rigging in which the brushes are readily removable. The springs 38 and clips 33 are interconnected and thereby form an endless fleXib-le brush retainer for all the brushes. This retainer can be removed as a unit. The yielding springs 38 permit the clips 33 to be withdrawn from the slots 31 and 32. After the clips are removed, the brushes can be readily withdrawn.

While the walls 27 and 28 of the brush guide are shown at a substantial angle to the radius and the wall 35 of the brush clip 33 is long, it will be understood that beneficial results may be obtained by disposing in the drawing and likewise that the length of the wall 35 may be Varied within wide limits within the scope of the present invention, the essence of the present invention being that the brush 30 is at all times hplld in non-chattering contact with the wall 2 The invention is herein shown as applied to a motor ot'the type in which the brushes are all electrically connected to one another at all times as, for example, a repulsion-induction motor, but it is to be understood that the brush holders 25 can be insulated from one another and the clips 33 can be suitably insulated from one another to suit the requirements of other types of electrical apparatus.

While the form of mechanism herein shown and described constitutes a preferred embodiment of one form of invention, it is to be understood that other forms might be adopted and various changes and alterations made in the shape, size, and proportion of the elements therein without departing from the spirit and scope of the invention.

What is claimed is as follows:

1. A brush rigging comprising in combination, a brush, a brush holder for slidably supporting the brush, said brush holder having a brush sup-porting wall engaged by one side of the brush; an means for yieldingly maintaining the brush in engagement with said wall.

2. A brush rigging comprising in combination, a brush, a brush holder for slidably supporting the brush, said brush holder having a brush supporting wall engaged by one side of the brush; and means for yieldingly maintaining the brush in engagement with said wall, said means including springs connected with the brush and extending in diverging relations from the brush.

3. A brush rigging comprising in combination, a brush, a brush holder for slidably supporting the brush, said brush holder having a brush supporting wall engaged by one side of the brush; and means for yieldingly maintaining the brush in engagement with said wall, said meansincluding springs connected with the brush and loneoaeee cated in such positions that the resultant of the forces applied thereby to the brush is directed toward said wall of the brush holder.

4:. A brush rigging comprising in com bination, a brush, a brush holder for slidably supporting the brush, said brush holder having a brush supporting wall engaged by one side otthe brush; and means for yieldingly maintaining the brush in engagement with said wall, said means including springs and a member having ends each attached to one of said springs and an intermediate portion bearing against the brush.

5. A brush rigging comprising in combination, with a commutator, a brush, a brush holder for slidably supporting the brush, said brush holder having a brush supporting wall engaged by one side of the brush; and means for yieldingly maintaining the brush in engagement with said wall, said means including springs and a member having ends, each attached to one of said springs, and a portion bearing against the side of the brush making an obtuse angle with the commutator.

6. A brush rigging comprising in combination, brushes, brush holders for slidably supporting said brushes, said holders each having a brush supporting wall for engaging one side of a brush, a plurality of springs each located between adjacent brushes, and devices each for connecting the adjacent ends of springs and for causing a brush to be forced against a brush supporting wall.

7. A brush rigging comprising in combination, brushes, brush holders for slidably supporting said brushes, said holders each having a brush supporting wall for engaging one side of a brush, a plurality of springs each located between adjacent brushes, and devices each for connecting adjacent ends of springs to provide a continuous brush retainer, and for directing th resultant force applied by the springs to each brush in such a manner that each brush will be pressed against its supporting wall.

in testimony whereof ll hereto aiiix my signature.

JUHN G, CAMPBELL, 

